Screw-cutting machine



Patented Ocie I6, 1923.

msmee ssems mzeeee MIME @Wiee RUDOLIPH BOEH1VI, OF ERIE, IENNSYLVANIA, ASSIGNOR T RIOKERT-SHAFER COM- PANY, DIE ERIE, PENNSYLVANIA, A CORPORA'I'ION OF PEN'NSYLVANIA.

Application filed April 7,

T0 all w/wm zzfi mag concemf Be it known thatL RUDOLPH A. BOEHM, a eitizen of ehe United Statesresiding et Erie, in the county 0f Erie and State of Pennsy1- 5 vania, have invented certain new and useful Improvements in SereW-Cutting Machines;

and I do hereby declzire the rr.'0llowing t0 be a fu1l, elear, und exact descrijgtion of the invention, such as will G1mble others skilled in Ehe art to whieh it appertains to make and use the same referenee being had 110 the accompanying drawings, and so the 1etters of reference mark 3d thereon, forming part 0f this specifieation. 'I his inventi0n relates o screw cutting attaehments fror 1athes und other machines, and it relates more particularly to mounting screw Cutting dies in tandem' so es to cut simultaneously, two 01' more threads at different points in the lengfln f a rod.

The objeet of my invention is t0 provide sui'table mechaiuism adapted t0 be placed upon a leihe which Will cut threads upon a rod at a plurality of points in the lengt-h thereof simultaneously.

Another objeet of my invention is to provide mechanism which Will cut tapered threads at one p0int and stmight threads at another point. 1 3

In cerrying out the objeets of my inventi0n I mount upon the Slide-ways of a lathe a platform whi.eh cn be inoved longitudina1ly 0n Seid slide-waj s by the ordinary hzind-feed mechenisrn of -the lathe, and upon ing dies so that -the axes of seid dies are 011 the 1ine 0f the axie of the spindle 01 the lathe. 'Ihe threading dies 'whieh I vse f01 this purpose are of the type shown and de- 676 issued upon my epplieation, December l, 1914 in which the chasers automatically open efter the desired number of threads have been eut. This opening und closing movement of the chasers is eceompanied by a rotury movemen't of 0ne portion of the die holder es described in seid pate1itfof Whieh a handle was provided in seid patent.

Inthe present invention Iprovide camlevets which are adapted to (angage the operating handles ef the die holders, and es the platform czirryingg the die holders is moved toward the lathe spindle, seid haudles engage said cam-levers end rotate the r'otatable porti0n. 0f the die holders to close this platfrm Imount one 01 :m0re threadi scribed iIi U. S. Letters Patent N0. 1,119,

1.922. Serial N0. 5509366.

Ehe ehasers, and the chasers ere thereby maintained closed until the die holder han dles pass beyond Ehe ends 01 seid cmn-IeverS when the dies automatically open es desc1ibed in seid patent.

-011 the baekward mo vemen oi the platform and die holdefs seid camlevers ere adapted to allowthe'die holder handles to pass over their upper edges.

These and othe r features 0f my inviantion are hereinafter 'more fully set"forth ahd pointed out and 2tre illustrzited in the accompanying drawings in which Figure l, is a fr0nt elevatioh ofa portion of' a lathe proizided with my imPpoved screw-Cutting attaehments.

Figure E2, is 2i plan view ofthe same.

In these dreivings A indicat'es the fr'ame of a 1athe, portions thereof being broken away; a a indica tes the usual slide-vvsys on seid frame, 'A' indicates the usual lathe/ spindle, und A indicates a ehuck seeured 011 the spindle A; seid chuck beingedapted to receive the squzire* end of a work-piece, es hereinafter described. A is a head-stoek bracket in which the spindle A is journalled.

Upo n ehe s1ide-ways au I plaee a platform B which is provided with thei1sual hand-feed -IeverS B, and gear and rack mechanism -(1101:- shoWn) f0r[ moying the platform ]ongitudinallyon the slideweys a a. This platform B is preferatbly proVided with longitudinal key-slets b b. WI1I I1 are adapted to reeeive the hezidsbf bolfis,

as hereinaftet described. Upon the-lolatfonn B I place braekets C, C/which are securead in proper p0sition 011 Ehe platform f01 the work required, by mealns 0f bolts c, the heads 0f whieh are in the key:slots b 7). Secured in the brmckefs C and C aie Ehe :shanks D and D of the die holde1s D and -D by means 0f sei: serews 0', the bmekets C and C supportihgthie die-holdem D and 4100 D on the line Cf the aXis 0f the spindle A.

The die holders D and D are 0f the type shown and described in the U. S. patent ;hereinbefore mentioned being spring p erate'd in the opening direction, und nm nn ally operated by meansof the 1ever d in the closing directi0n. They are als preferably -provided With a stop (l forthe pi1rpose hereinafter des'cribed. d of the die holders with a, roller d.

The 'cl0sing levers -eure prefembljprqvided Secured on the lathe frame A are braekets E E E in -the upper end of which is secured a shaft E by me'ans oi set sorews e. Upon the shaft E are placed blocks F and F, seid blocks being i'etz'rined in tlieir longitudinal positi0l 'on seid Sliaft b y means of set screws Upon the block F I secure a stelionary guide-plate G which is provided wi.th an upwardly inolined surfirce and pivot'ed between the guide-plate G and the block F, by me2ins o1" the' pivot SCIGW g is a cam-lev er H, wliich swings upori the pivotsorew the upward m0vement thereoi being limited by the guide-platie G.

The carn-lever H is yieldingly meintained in the positi0n showh in Fig. l, by means of a spring g so that when seid lever is pressed downvvard as hereinafter described, it Will return to its norxi1zzlly r2iised position When released.

The guide-plnte G 2u'1d lei er H ere de signed t'o oljerete the die holder D- to cut a tapered thr eaid 'shereinziftei: described.

Up0n the block is pivoted a oa1ri-lever J by fr1eaansof a pivot s'crew j, sa;idlever being provided With a re'arwardly extending portion J the portion J being piovided with a transverse slot j in which a post j se'cred in the block F operates to limio that when th post j? stops tl1e Swing of 'said lever the lower edge of the portion J of the lever J ispaiallelwith the axes of the die holders D and D3.

The le'veY is' designed to operate the die holder D to Cuta thread of Uniform diemeter es hereinafter described.

Seoured fu'pon the platfornf1 B are posts 1& With whioh the stop arms d contuet wheh the irrms d on the dieholders D 2ind D lass around the rear ends of the guideplate Ei er1d lever J*J' s0 asdto limit the spring iotiiiited joening novernencof the rotatable portion of the die-holders.

In operation a stay-loolt L or other rod which is required to be threeded is pessed th'rough the opendiehold'ers, ai1d the scji1are en'd Z thereof is insertedinto the chuek A on the spindle A; The r"eed Wheel B is then operated to force the plaform B fo1= Ward, Wl1lch cerries the dieholders D 2md D towerd the orlr-piece to be -fihreeded; the rollers d on tlie handle d of the die holdersD 2111(1D3 2'Lre "erlgaged b'y t-l1e 021mlever s G and J and are thereby, during the eonti'nued 'movernent- 'of the die-holders,

' forced to sWing downwarjd thus Causing i;he

roi;ation of the rotat able portions of the die holders which eau'ses tlie ehasers to close inwardly 130 their Ciitting positio'n.

'lhe roller al on the handle d of the die i holder l) frzflvels downwa rdl y along bhe inclin'ed l nder edg'e of the eam-lever J until it Passes opposite the pivbt sore wj when the portion J of seid lever swings upward until it is stopped by the post j* with its lower edge parallel with the axes of the die hold ers, when the chasers in seid die holder comrnerice cutting a thr'ezid L oh the stayholt. Meanx'vhile tl1e roller 0Z on the handle (Z of the die holder D having passed dowm -wardly along the under inclined edge of the cam-lever H, has also closed the chasers in tlie die holder D t0 their cutting position, and seid roller continues to travel alonq the under edge oi the guideplate G until it begi ns to travel along the upwardly inelin ed under edge g of Seid pla te, which pei*mits alle ggradual opening of the chaseis ward, Whieh carries the rollers'd 0Verthe upper edges olt' the c22rn leve'r's H a1id J, swinging s2iid levers downivard es they pass thereover.

The work-piece L is then removed. The free end's 0f tlie cam levers H and J are curved toward the die holde'rg 130 adapt them to the eircular movement of the rollers d during the closing of the die hO-lders.

Jirorn ehe foregoing descripfiion 01E the constituction and Operation it Will be apparent to those skilled in t he art th2it a'r'1y desired number 0f die-hold'iars cai1 be em ployed whioh may be reqiiired fo simulraneously out threads ab desired points 011 the work-piece; also that all of th'e threads may be tapered, or all may be of uniform dizimeter, as desired.

The placing of the blocks F and F upon the shaft E et the proper position for the Work required Will be eaSily determineid by the operat'ot.

Having th1is fully described 1ny invention so es to enable others to utili'ze Ehe Same, I do not desire to be limited to the exact mechenisin shown Ellld descriloed, es many modifications ce'n be ndade therein without departing from the scope of n 1y in vention; therefore what l olaim as new and desite 130 secure by Letters Patent lSI- l. In 2 machine of the dass describead, 2r self opeiiinjg'die holde'r, an operating arm thereon. and :rrieans supporte;d in the horizo'ntal path of feed travel of sziid arm adapted vto engage seid operating: arm to olose seid die holder a11d c0-ntrol the Opening of the same.

2. In a machine of the dass described, a self opening die holder, an o'pereting arm thereon, an inclined gide niechanisrn' sup- Ported adjacent to seid die holder a'uid IUl edapted to engege end move Seid erm to close seid die holder end guidesaid arm during the threed cutting 0peretion.

3. In a mechine of the cless described, e seli opening die holder, en opereting arm thereon, eninclined guide mechenism supthe reoeding movement oi seid die holder,

to its Initial position.

4i-. In a maohine of the dass desoribed, e self opening die holder, an opereting arm thereon, a vertically swinging guide Supported edjeceni to seid die holder, meens to yieldingly maintein seid guide in, its operative position so thet it Will engege seid die operefiing erm end ceuse it to close seid die holder es the seine moves forwerd to its work end control the degree of closure of seid die during the threed cutting operation until seid opereting erm pesses beyond seid guide,yend 130 permit seid opereting arm to pass over seid guide duri'ng the re cession of seid die holder 130 its initiel position.

5. In e mechine of the dass deseribed, e freme, slide-weys thereon, e pletform 011 seid slide-weys, mechenism 150 move seid pletform longitudinelly on seid slide-weys,

a heed-stock on seid freme, e spindle mounted in seid heed-stoek, a self opening die holder secured on seid pletforin, an

' opereting arm on seid die holder, breckets secured onseid freme, e bar secured in seid breckets and parallel With the exes oi seid spindle end die, e block secured 011 seid her, an inclined guide pivoted 011 seid block and positioned in the peth of trevel 0f seid operetin sz arm, end edapted to engege end move seid ermio ceuse seid die holder to close end guide the Same durmg the "chread cutt1ng operat1on.

6. In e mechine of the dass desoribed, e

frame, slide-waye thereon. e pletform on seid slide-weys, mechanism 120 move seid pletform longitudinelly on seid slide-weys, e plurelity of die holderSmounied on seid platform in speced reletion to eeeh other,opereting erms on seid die holders, meens to edjust the speced reletion of seid die hlders,

a heed stoek 011 seid frame, e spindle in seid heed stock on the exiel line of seid die holders, breckets on seid freme, e her supported in seid breckets parallel 130 the exis RUDOLPH A. BOEHM; 

